According to this Meta thread, this would appear to be an issue with Google Code Prettify, however syntax highlighting for both Powershell and Batch works if it's specified manually:

• Doesn't Work:

  • ```bat
    

  • ```powershell
    

  
  
• Works:
  • <!-- language-all: lang-bat -->
<!-- language: lang-bat -->
  • <!-- language-all: lang-powershell -->
<!-- language: lang-powershell -->
    
    

Is the latter implemented by Superuser locally and not via Google Code Prettify, else why the disparity?

• I'm not familiar with how StackExchange sites individually function, but wouldn't it be a lot simpler if shell languages were supported the same across all sites that apply to code?
  
  For example, syntax highlighting for both Powershell and Batch are auto-applied on StackOverflow.